ABSTRACT
Background and purpose:Colorectal cancer (CRC) is a malignancy which is the third incidence and the fourth mortality in the worldwide. The main reason for the development of CRC is that the changes of genetic and epigenetic causes the tumor suppressor gene methylation silencing. This study aimed to investigate the plasma and stool GATA5 gene promoter methylation was detected in clinical diagnosis of CRC. Methods: To collect the paired plasma and stool specimens of 34 cases of healthy and 43 cases of patients with CRC. Methylation speciifc PCR (MSP) was respectively detected the GATA5 gene methylation levels of GATA5 gene in plasma and stool. And then separately analyzed their correlations with clinical and pathological parameters in gastric carcinoma. Results: The result of MSP showed that GATA5 gene promoter methylation rates in plasma and stool of CRC patients were 60.74%, 76.60%, respectively, were higher than those of healthy persons (6.47%, 32.35%). And the differences were statistically signiifcant (P=0.006 7, P=0.000 2, respectively). GATA5 gene methylation rates in plasma of CRC patients were closely related to clinical stage (P=0.000 5) and lymph node metastasis(P=0.020), while GATA5 gene methylation rates in stool of CRC patients had no signiifcant with clinical and pathological parameters. Conclusion:Detection of faecal GATA5 gene methylation level and supplemented plasma GATA5 gene methylation level can become a simple, non-invasive, sensitive and speciifc method for clinical diagnosis of CRC.
ABSTRACT
Background and purpose: At present, gastric cancer is considered to be both genetic and epigenetic disease, and epigenetic alterations play a significant role in the development of gastric cancer. DNA methylation is the most well studied and most in-depth epigenetic modiifcations in human-beings. The silencing of tumor-related genes by DNA methylation is reversible. ERCC1 is a kind of DNA repair gene. The present study was aimed to detect the CpG island methylation status of ERCC1 gene promoter in gastric cancer tissues and corresponding peripheral blood, and to explore the relationship between methylation of ERCC1 gene in peripheral blood and in gastric cancer tissues. Methods:Methylation speciifc PCR was performed to detect the methylation status of ERCC1 gene in the tumor tissues and the paired peripheral blood from 30 gastric cancer patients. Results:The positive rate of methylation of ERCC1 gene promoter CpG island was 76.7%(23/30) in the tumor tissues and 63.3%(19/30) in serum of gastric cancer patients, and the difference had no statistical signiifcance. Conclusion:Our studies suggest that ERCC1 gene promoter CpG island methylation can be detected in a high proportion of the serum consisting with that in tumor tissues of gastric cancer patients, and the detection of methylation status of ERCC1 gene in peripheral blood provides a more simple, fast and reliable way for the medical treatment of gastric cancer and also provides the possible theoretical basis for the CpG island methylation of ERCC1 gene promoter as a target for the treatment of gastric cancer.